1. Field of the Invention
The present invention relates to apparatus for counting objects and, more particularly, to apparatus for counting elongated cylinders such as beverage containers.
2. Description of the Prior Art
Several of the United States have laws requiring retail vendors of beverages to collect a deposit on each container when the beverage is sold and refund this deposit when the empty container is returned. In fact, a bill is currently before Congress which would require a nationwide deposit on "returnables." The objects of these "bottle bills" are (1) to reduce litter and (2) to encourage recycling, thereby conserving resources used in manufacturing the containers. Counting returned, empty containers is crucial under these laws because of the deposits involved.
Obtaining an accurate count of and collecting deposits for containers sold is relatively easy because the containers, such as bottles and cans, are generally packaged for sale in cartons, cases and/or plastic connecting strips. This packaging enables the retailer to quickly and easily count the containers on which a deposit is collected. However, counting the number of empty containers returned is extremely difficult because these containers, especially cans, are usually returned in bulk, for example, in paper or plastic bags. These containers are returned in bulk because this is the easiest way for consumers to return the cans to the store.
Consequently, counting the returned containers presents a difficult problem for both the retailer and the distributor, to whom the cans are ultimately returned. A number of prior art counting methods have been developed, none of which is both cost efficient and accurate.
The most common way in which the returned cans are counted is to have individual workers visually count each can. The worker may either (1) physically handle and count each can or (2) count the cans as they pass by the worker, for example, on a conveyor. Obviously, this approach has significant drawbacks. First, it requires a relatively large labor force, which is extremely expensive. Second, the counts may be inaccurate because of human error due to day-dreaming and inattention among other reasons.
A second prior art approach to counting the returned cans is to weigh the cans in bulk. Although this method proceeds fairly rapidly, the counts provided are generally inaccurate. This is because other material such as residual liquid in the cans, biases the count upwardly. Because the cans are relatively light, even a small amount of additional material can throw the count off. Furthermore, different brands of cans often have different individual weights, which affects the can count, and cans vary in size according to their capacities (e.g., 12 or 16 ounces).